2,6-Dihalobenzaldehyde Sulfonyl Hydrazones

ABSTRACT

The substitution of semicarbazones of 2&#39;&#39;,6&#39;&#39;-dihalobenzaldehydes by 1-alkyl groups and 3-alkylsulfonyl or 3-arylsulfonyl groups, provides compounds which are active plant growth regulators. Plant growth regulation provides a more efficient means of growing food-producing plants and the like.

United States Patent 91 Fridinger et al.

[ 1 Feb. 4, 1975 2,6-DIHALOBENZALDEHYDE SULFONYL HYDRAZON ES [75]Inventors: Tomas L. Fridinger; Edward L.

Mutsch, both of Woodbury Twsp., Washington City; David R. Pauly,Stillwater, all of Minn.

[73] Assignee: Minnesota Mining and Manufacturing Company, St. Paul,Minn.

[22] Filed: Oct. 16, 1972 [21] Appl. No.: 297,970

Related U.S. Application Data [62] Division of Ser. No. 90,074, Nov. 16,1970, Pat. No.

[52] U.S. Cl. 260/556 H [51] Int. Cl. C07c 143/74, C07c 143/78 [58]Field of Search 260/556 H [56] References Cited UNITED STATES PATENTS2,962,511 11/1960 Zimmer 260/3977 R 3,129,257 4/1964 Paquette 260/556 HFOREIGN PATENTS OR APPLICATIONS 538,462 ll/1955 Belgium 260/556 HPrimary Examiner-Henry R. .liles Assistant Examiner-S. D. WintersAttorney, Agent, or FirmAlexander, Sell, Steldt & DeLal-lunt [57]ABSTRACT The substitution of semicarbazones of 2 ',6 dihalobenzaldehydesby l-alkyl groups and 3- alkylsulfonyl or 3-ary1sulfonyl groups,provides compounds which are active plant growth regulators. Plantgrowth regulation provides a more efficient means of growingfood-producing plants and the like.

7 Claims, No Drawings BACKGROUND OF THE INVENTION The compounds of thepresent invention are substituted semicarbazones of certainbenzaldehydes. More specifically they are semicarbazones of 2.6'-dihalobenzaldehydes substituted by l-alkyl groups and 3-alkylsulfonyl or3-arylsulfonyl groups. The compounds of the present invention are usefulas plant growth regulators and may be used with other various suitableadjuvants, both inert and active.

The problem of population explosion and food shortage have become quiteserious recently and are widely acknowledged. The search for methods toimprove the efficiency of agricultural production continues vigorouslyand in many ways. Equipment, improved varieties of plants and chemicalcontrol of plant pests continue to advance in sophistication. Plantgrowth regulating chemicals have the potential to play an important rolein the struggle against hunger. Such chemicals may be compared tohormones and other food supplements to the human diet as they help theplant to do a more efficient job in its production of food.

Plant growth regulating utility is relatively uncommon, although widelysought. In some cases chemical compounds may be plant growth regulatorsat low con-' centrations and may be very phytotoxic, that is herbicidal,at high concentrations. An example of this is 2,4-dichlorophenoxyaceticacid. In fact, the term plant growth regulator" is sometimes used toinclude herbicidal properties, although it is not used herein in thatsense. Plant growth regulators may stimulate or retard growth of theplant or may affect the growth of one particular part ofthe plantwithout affecting other parts of the plant. In some cases, plant growthregulators may be found which direct the energy of the plant to aparticular aspect of its development which is most desirable, that isthey may increase the yield of the edible portion of the plant. This mayoccur by a variety of mechanisms, for example increased flowering, increased bud set, enlargement of the edible portion and the like. Sucheffects are particularly advantageous.

The methods for distribution of agricultural chemicals in general, andplant growth regulators in particular, utilize the scattering of arelatively small amount of diluted material over a large area. Examplesof regulators so used are maleic hydrazide and gibberillic acid.Accidental localization of the effective ingredient can occur. however,resulting in phytotoxicity if the ingredient is herbicidal at higherconcentrations. For this reason plant growth regulators with very lowphytotoxicity would be desirable.

SUMMARY OF THE INVENTION According to the present invention there areprovided compounds of the formula x Q ca-u-mrso mn' uco wherein X ishalogen; R is alkyl and haloalkyl having from one to four carbon atoms.phenyl and substituted phenyl; and R is alkyl having from one to fourcarbon atoms. The compounds find use as plant growth regulators and havethe advantage of little or no phytotoxiclty.

ln the preferred embodiment of the present invention. X is chlorine orbromine, although it may also be fluorine or iodine. Preferably, one Xis always chlorine. In the most preferred embodiment, both X's arechlorine as the corresponding starting materials are most readilyavailable.

R may be a straight or branched chain alkyl of one to four carbon atoms,but is preferably methyl or ethyl, methyl being preferred. R may bestraight or branched chain alkyl of one to four carbon atoms, but it ispreferably methyl or ethyl, methyl being preferred.

When R is haloalkyl having from one to four carbon atoms, the halogenmay be fluorine, chlorine or bromine, but is preferably fluorine orchlorine. In the preferred embodiment, R is generally one or two carbonatoms partially halogenated. Most preferred are compounds wherein R ischloromethyl or fluoromethyl.

When R is substituted phenyl, one to five Substituents may be present onthe ring. These substituents may be the same or different. Substituentswhich may be present include halogen, alkoxy, alkyl, nitro andhaloalkyl. Presently preferred Substituents are halogen and alkoxy.

The compounds ofthe invention are prepared, generally, by the reactionof novel 2,6-dihalobenzaldehyde alkyl-, haloalkyland arylsulfonylhydrazones with alkyl isocyanates. This reaction is preferably carriedout in a suitable nonreactive solvent which dissolves the hydrazone, forexample ketones such as acetone, esters such as ethyl acetate,halogenated hydrocarbons such as dichloromethane, and the like. Anexcess ofthe isocyanate is generally used to facilitate the reaction.The reaction may be run at room temperature, but generally requireshigher temperatures, such as the reflux temperature of the solvent, andmay require extended refluxing for two to three days although refluxingfor l to 48 hours has been found sufflcient for most applications.Preferably, the reaction is run in the presence of a suitable catalystsuch as a tertiary amine of which triethylamine is most preferred.

Because the reaction is sluggish, it may be necessary to separate theproduct from unreacted starting material by fractional crystallization,selective extraction or elution chromatography. The products obtainedare generally solids. The synthetic reaction is illustrated by thefollowing equation:

tion is 0.25 to 1.0 percent. The plants were checked The alkylisocyanates useful in the process of the weeks. Such an effect isextremely desirable. suggesting above equation are well known in theart. The novel hythat more plants could be planted in a given area whiledrazone intermediates are prepared by the reaction of each plantproduces more beans. a 2,6-dihalobenza1dehyde with an alkylsulfonyl,Among the most active of the compounds were the haloalkylsulfonyl orarylsulfonyl hydrazine. Some 2.6- 5 following: dihalobenzaldehydes arereadily available and some 21'6l dichlombenzaldehyde others are reportedin the chemical literature. See, for (methanesulfonyl)semicarbazoneexample Lock Ber'chte page 2,6'-dichlorobenzaldehydel-ethyl-3-(methanesul- (1935); J. F. Bunnett, et a1, J.A.C.S., Vol. 83.page fonynsemicarbazone 2512 (1961); and British Pat. No. 1.080.167.issued 6i dichlorobenzaldehyde l methyl 3 (ethancsul Aug. 23. 1967. Allof the 2.6-dihalobenza1dehydes are ifonynsemicarhazone available throughthe use of the synthetic techniques l dichlombenzaldehyde reported forthe preparation of such compounds. Somegromobenzenesulfonyl)Semicurbazone of the alkyl and arylsulfonylhydrazides are known in 26[dichlorobenzaldehydel methy| 3(benzcncsup the art, and all of the hydrazides may be prepared byfonynsemicarbazone known synthetic methods such as reaction of thesulfot 6l dichlombenzaldehyde 3- 4 nyl halides with hydrazine. The novelhaloalkylsulfonyl ;nethoxybenzenesulfonyl)Semicarbazone hydrazidesdisclosed herein are not reported in the literature. 7 The followingnon-limiting examples are given to il- The novel hydrazone intermediatesof the invention lustrate the invention more specifically. particularlyare prepared according to the following reaction: with respect to thepreparation of the novel intermedix or x The hydrazide is first reactedwith the benzaldehyde. 310 ates and novel and valuable compounds of thepresent The mixture is then dissolved in refluxing ethanol andinvention. the reaction is heated at reflux tem erature (a roximately80C.) for one to several hliurs to insEr e the EXAMPLE I completion ofthe reaction. The product generally is To a stirred mixture of 7.3 gm of4- obtained as a solid precipitate upon cooling of thereachromohenzenesulfonylhydrazide (0.029 mole) in 50 tion mixture. ml.of water is added to a solution of 5 gm. of 2.6- The plant growthregulating activity of the comdichlorobenzaldehyde (0.0286 mole) in 50ml. of ethapounds of the invention was observed by known no] in onebatch. A solid precipitates and 500 ml. of screening tests on severalplant species. The plants ethanol is added. The mixture is heated toreflux and were sprayed to run-off with a solution of the novel 40maintained at reflux temperature for one hour. The socompounds of theinvention in acetone with a surfaclution is then filtered hot andallowed to cool slowly. tant such as Tronic which is a mixture of alkylaryl The precipitate is collected by filtration and washed oxyethyleneglycols mixed petrolium distillates, alkyl three times with 75 ml. ofwater. The white solid is 2.6- sulfates and alkyl amine acetatesmanufactured by Coldichlorobenzaldehyde 4-brom0benzenesu1fonylhydraliodal Products Co. The concentration of the chemical Z0116. p. 18ll33C.

is 2,000 parts per million and the surfactant concentra- ,t'" I I dailyfor any effect or alteration on the development of K m the plantcompared to untreated controls. The com- Calculated for C,;,H,,BrCl N OS: 38.3 2.2 (1.9 pounds of the invention were found to be active inproducing plant growth regulatory effects. In particular, bean plants(Pinto beans) were found to undergo Other 2,6-dihalobenzaldehydearylsulfonyl hydradwarfing of the plant with increased bud and beanprozones which are prepared according to the method of duction. Suchregulation was noted after two to three 5; Example 1 are given in thefollowing table.

'l'ABLli l Melting Ex. Nu. Compound Point (in 2 2.6-dichlorohenzaldchydebcnzcncsulfonyl -130 hydrazone 3 Afr-dichlorobenzaldehyde4'mcthylbenzcnc- 189-193 sulfonyl hydrazonc 4 2.o-dichlorobenzaldchyde4-nitrobenzencsul- 193-197 fonyl hydrazonc 5 2.o-dichlorobcnzaldchyde4-methoxybcnzene- 1455-1495 sulfonyl hydrazonc 62,6-dichlorobenzaldehyde 4-fluorohcnzenc- 179-181 sulfonyl hydrazoneTABLE I -Continued Ex. No.

Compound 9 Z.b-dichlorohenzaldehyde Z-nitrohenzenesulfonyl hydramne2.h-diehlorohcnzaldehyde RA-dichlorohenzenesulfonyl hydrazonc2.fi-dichlorobenzaldchyde 2.5-dichlorobenzenesulfonyl hydrazone2,6-dichlorobenzaldehyde 4-chloro-2- nitrobenzcnesulfonyl hydrazont:

2.6-dichlorobenzaldehyde pentafluoro bcnzenesulf'onyl hyd razonc2.fi-dichlorobenzaldehydc 4-chloro-3- nitrohcnzencsulfonyl hydrazone2.6-dichlorohenzaldehyde 2,3,4-trichlorohenzencsulfonyl hydrazonc2,6dichlorobcnzaldehyde 4-trifluoromethylhenzenesulfonyl hydrazoneEXAMPLE l7 To a stirred solution of 7.7 gm. of methanesulfonylhydrazide(0.07 mole) in 75 ml. of water is added a solution of 12 gm. of2,6-dichlorobenzaldehyde (0.069 mole) in 100 ml. of ethanol in onebatch. A solid precipitates after which 300 ml. ofethanol is added. Thesolution is heated to reflux temperature and maintained at reflux forone hour. The mixture is filtered hot and allowed to cool slowly. Theprecipitate is collected by Melting 7 Point (in *C.)

stirred at room temperature for about 65 hours, then heated to refluxand maintained at a reflux temperature for one hour. The solvent isremoved by evaporation in vacuo to give an oil which crystallizes. Thesolid is recrystallized twice from a hexane chloroform mixture to givewhite solid 2,6'-dichlorobenzaldehyde l-methyl3-(methanesulfonyl)semicarbazone, m.p. l09-l 14C.

filtration and washed thoroughly with water. The white 35 solid is2,6-dichlorobenzaldehyde methanesulfonyl hy- Analysis: ltC (/IH mdrazone Calculated for c..,H,,ci. .N..o,.s; 37.1 3.4 13.0 Found: 37.03.4 [3.0

40 Analysis: /L C 91H ZN Calculated for C,,H,(Cl N O S: 36.0 3.0 10.5 MLE 23 Found: Ethyl isocyanate is reacted with 2,6- dichlorobenzaldehydemethanesulfonyl hydrazone ac- 45 ti E I I 22 t h't 1d 2' o Other2,6-dihalobenzaldehyde alkylsulfonyl and Cor mg to Xdmpe 0 Prepare a wso] haloalkylsulfonyl hydrazones which are prepared according to themethod of Example 17 are given in the following table.

sulfonyl hyd razonc EXAMPLE 22 To a cold stirred solution of 9.0 gm. of2,6- dichlorobenzaldehyde methanesulfonyl hydrazone (0.034 mole) in l00ml. of acetone and 4 drops of triethylamine is added, dropwise, 4 gm. ofmethyl isocyanate (0.07 mole) in 30 ml. of acetone. The mixture isdichlorobenzaldehyde l-ethyl-3-(methanesulfonyl)- semicarbazone, m.p.ll4-l20C.

semicarbazone, semicarbazone, a white solid, m.p. l031l2C.

Analysis: 71C "/tH N Calculated for C H CI N O S: 39.] 3.9 l2.4 Found:38.9 4.] I25 EXAMPLE 25 To a cold stirred solution of 8.8 gm. of 2.6-dichlorobenzaldehyde 4-bromobenzenesulfonyl hydrazone (0.022 mole) in 90ml. of acetone and 4 drops of triethylamine is added. dropwise. 2.3 gm.of methyl isocyanate (0.04 mole) in 20 ml. of acetone. The mixture isstirred cold for two hours. then at room temperature for about sixteenhours, and finally it is heated to reflux and maintained at refluxtemperature for one hour. The solvent is removed by evaporation in vacuoto give a solid which is recrystallized from a hexane-chloroformmixture. The first crop of precipitate is separated and is found to bestarting material. The filtrate is partially evaporated and a secondcrop is collected which is found to be starting material. Furtherevaporation of the filtrate gives a third crop which is found to bedifferent from starting material according to its infrared spectrum.When this third crop is again recrystallized dichlorobenzaldehydebenzensulfonyl hydrazone according to Example 25 to prepare 2.6-dichlorobenzaldehydel -methyl-3-( benzenesulfonyl semicarbazone. a whitesolid. m.p. lO9-l lC.

dichlorobenzaldehyde 4-methyoxybenzenesulfonyl hydrazone according toExample 25 to prepare 2,6- dichlorobenzaldehyde l-methyl-3-(4-methoxybenzenesulfonyl)semicarbazone, a white solid, m.p. l43-l47C.

from a hexane-chloroform mixture, the white solid product is2',6'-dichlorobenzaldehyde l-methyl-3-(4-bromobenzenesulfonyl)semicarbazone, m.p.

o 0 I21 l25 C. Analysis r/lc I/IH VIN C-ll't'df C H CLN'OS: 46.1 3.6l0.l AnulFSiSi 71H 25 Mud L or m Fdurid: 46.0 3.7 10.0

Calculated for C -,H -,BrCI N,,O;,S: 38.7 2.6

Found: 387 2.7

Other compounds of the invention obtained from the M E 26 w reaction ofan isocyanate with a 2.6- EXA PL dihalobenzaldehyde alkylsulfonyl orarylsulfonyl hy- Methyl isocyanate is reacted with 2.6- drazone areshown in the following table:

TABLE III Example REACTANTS Number Isocyanate Hydrazone Product 28methyl l-chloro-o-fluorohenzaldehyde 2-chloro-6-fluorobenzuldehydemethanesulfonyl lmethyl-3( methanesulfonyl semicarhazone 29 ethyl2.6-dichlorohenzaldehyde 2.6-dichlorohenzaldehyde l-ethyl-4-nitrobenzenesulfonyl 3-(4-nitrohcn2cnesulfonyl)semicarhazone 30n-hutyl 2.6-dihromohenzaldehyde 2.6-dihromohenzaldehyde ln-hutyl-4-bromohenzcncsulfonyl 3-(4hromohcnzenesulfonyl )scmicarhazone 3]isopropyl 2.fi-dichlorohenzaldehyde 2.fi-dichlorobenzaldehydel-isopropyl- 4-methoxyhenzenesulfonyl3-(4-mcthoxyhenzenesulfonyl)scmicarbazone 32 methyl2.6-dichlorohenzaldchyde 2.o diehlorohenzaldehydel-methylisopropancsulfonyl B-(isopropanesulfonyl)semicarhazone 33 methyl2.6-diiodobenzaldehyde 2.6-diiodobenzaldehyde l-methylmethanesult'onylS-(methanesulfonyl)semicarbazone 34 methyl Z-chloro-6-hromohenzaldehyde2-chloro-6-hromohe nzaldehyde- I -methylmethanesulfonylB-(methanesulfonyl)scmicarhazone 35 methyl 2,o diehlorohenzaldehyde2.(i-dichlorohenxaldehyde l-methyl-3- 4-triflutlromethylbeuzenesul(4-tritluoromethylhenzenesulfonyl l'onyl semicarhazone 36 methylZJi-dic'hlorohenzaldehyde 2,h-dichlorohenzaldehyde l-methyl-3-J-tluorohenzenesulfimyl (4-fluorohenzenesullonyl)semiearhamne 37 methyl2,6-dichloruhenxuldehyde 2.6-tlichlorohenlaldehyde l-methyl-3.J-dichloruhenzenesullhnyl 3-l 3,4-dichlorohenzcnesultonyl)scmicarhamne 3X methyl 2.o-dichlorohenzaldehyde 2(i-dichlorohenzaldehyde l-methyln-hutanesult'onyl 3-( n-hutanesull'on yl)semicarhazone 39 methyl 2.6diehlorohenzaldehyde2,o-dichloroheimildehyde l-methylpentufluorohenvenesuItonyl 3-(pentafluorohenzenesultbnyl) semicurhazone 40 methyl2.6-dichlorohenzaldehyde 2.o-dichlorobenzuldehyde l-methyl-3-4-methylhenzenesulfonyl (4-methylhenzcnesulfonyl)semiearhazone TABLE IllC ntinued Example REACTAN'I'S Numhcr lsocyanau: Hydrazonc Product 4]methyl 2.o-dichlorohcnzaldchyde 2,o-dichlorohcnzaldehydc l-mcthyl-3-chloromcthanesull'onyl ichloromcthanesulfonyl)scmicarhazonc 42 methyl2.o-dichlorohcnzaldchydc 2.o-dichlorohcnzaldchydc l-mcthyl-3-fluoromcthancsulfonyl (fluoromcthancsulfonyl)scmicarhazonc 43 methyl2,6-dichlorobcnzaldchyde 2.6dichlorohenzuldchydc l-mcthyl'f2.5-dichlorohcnzcnesulfonyl (2.S-dichlorobcnzcnesullbnyl )scmicarhazonc44 methyl 2.6-dichlorohcnzaldehydc l.fi'dichlorobcnzaldchydc l-mcthyl-L4-nitrohcnzcnesulfon \'l (4-nitrohenzcncsulfonyl )scmicarhazonc 45methyl 2.o-dichlorohcnzaldchydc 2.fi-dichlurohcnzaldchydc l-methyl-S-3-nitrobcnzencsull'onyl (J-nitrohemcncsulfonyl )semicurhuzonc 46 methyl2.6-dichlorobenzaldchyde 2.6-dichloruhcnluldchydc I-meKhyl-S-2.4,6-trimcthylhenzcncsull'onyl l2.4.6-trimethylbcnzcnesulfonyllscmicarhazune What is claimed is: bromobenzene sulfonyl hydrazoneaccording to claim I. A compound having the formula CH N NHSO R whereinX is halogen and R can be alkyl and haloalkyl having from I to 4 carbonatoms, phenyl and substituted phenyl wherein the phenyl substituents areselected from the group consisting of halogen, nitro and alkoxy, alkyland haloalkyl having from 1 to 4 carbon atoms.

2. The compound 2,6-dichlorobenzaldehyde 4-

1. A COMPOUND HAVING THE FORMULA
 2. The compound2,6-dichlorobenzaldehyde 4-bromobenzene sulfonyl hydrazone according toclaim
 1. 3. The compound 2,6-dichlorobenzaldehyde benzene sulfonylhydrazone according to claim
 1. 4. The compound 2,6-dichlorobenzaldehyde4-methylbenzene sulfonyl hydrazone according to claim
 1. 5. The compound2,6-dichlorobenzaldehyde 4-nitrobenzene sulfonyl hydrazone according toclaim
 1. 6. The compound 2,6-dichlorobenzaldehyde 4-methoxybenzenesulfonyl hydrazone according to claim
 1. 7. The compound2,6-dichlorobenzaldehyde 2,5-dichlorobenzene sulfonyl hydrazoneaccording to claim 1.